Ann: Trading Halt, page-109

Nb in carbonates:

- Average grade: 0.1-1.5% Nb2O5 (niobium oxide)

- High-grade deposits: 2-5% Nb2O5

- Exceptional cases: up to 10% Nb2O5

Nb in pegmatites:

- Average grade: 0.5-5% Nb2O5

- High-grade deposits: 10-20% Nb2O5

- Exceptional cases: up to 30-40% Nb2O5

Pegmatites tend to have higher Nb grades due to the concentration of Nb-bearing minerals like columbite and tantalite. Carbonates, on the other hand, may have lower grades but can still be economically viable depending on the size of the deposit and the extraction methods used.

In general Pegmatite will require more crushing as it’s a harder rock Carbonatites will require more acids depending on the individual deposits

Tantalite is what we are after in pegmatites where it dominates the Nb



https://www.sciencedirect.com/science/article/pii/S0169136814000638